Synergistic effects and related bioactive mechanism of Potentilla fruticosa L. leaves combined with Ginkgo biloba extracts studied with microbial test system (MTS)

Abstract

Background Potentilla fruticosa, also called “Jinlaomei” and “Gesanghua”, is widely used as folk herbs in traditional Tibetan medicine in China to treat inflammations, wounds, certain forms of cancer, diarrhoea, diabetes and other ailments. Previous research found P. fruticosa leaf extract (C-3) combined with Ginkgo biloba extracts (EGb) showed obvious synergistic effects in a variety of oxidation systems. The aim of the present study was to further confirm the synergy of P. fruticosa combined with EGb viewed from physiological bioavailability and explore the related bioactive mechanism behind the synergism.MethodsThe microbial test system (MTS) was adopted to evaluate the related bioactive mechanism. The synergistic effects were evaluated by isobolographic analysis. The H2O2 production rate and antioxidant enzyme (Catalase (CAT), Peroxidase (POD), Superoxide dismutase (SOD), Glutathione peroxidase (GSH-PX)) activities were determined by the colorimetric method. Enzyme gene (CAT, SOD) expression was measured by real time-PCR.ResultsThe MTS antioxidant activity results showed the combination of C-3 + EGb exhibited synergistic effects especially at the ratio 5:1. Components of isorhamnetin and caffeic acid in C-3 and EGb displayed strong antioxidant activities on MTS and their combination also showed significant synergy in promoting H2O2 production. The combinations of C-3 + EGb and isorhamnetin + caffeic acid promoted CAT and SOD enzyme activities and the ratio 1:1 exhibited the strongest synergy while no obvious promotion on POD and GSH-PX enzyme activities was found. Both combinations above promoted gene expression of CAT and SOD enzymes and the ratio 1:1 exhibited the strongest synergy.ConclusionsAntioxidant activity results in MTS further confirmed the significant synergy of C-3 combined with EGb and isorhamnetin combined with caffeic acid. The synergy of C-3 combined with EGb may be attributed to the combination of isorhamnetin + caffeic acid, which promoted CAT and SOD enzyme gene expression and further promoted the enzyme activities in E. coli. This study could further provide rational basis for optimizing the physiological bioavailability of P. fruticosa by using natural and safe antioxidants in low doses to produce new medicines and functional products.

Contribution of Individual Polyphenols to Antioxidant Activity of Cotoneaster bullatus and Cotoneaster zabelii Leaves—Structural Relationships, Synergy Effects and Application for Quality Control

“…The synergism between individual polyphenols or groups of these compounds may not only improve the properties of a singular raw material or extract but also positively affect the antioxidant activity of their various combinations. For example, the antioxidant activity of the leaves of Potentilla fruticosa, containing mainly hydrolysable tannins, was synergistically increased by the flavonoid fraction of Ginkgo biloba leaves [48].…”

High-Pressure Extraction of Antioxidant-Rich Fractions from Shrubby Cinquefoil (Dasiphora fruticosa L. Rydb.) Leaves: Process Optimization and Extract Characterization

“…The antimicrobial activity of D. fruticosa polar extracts against Gram-positive and Gram-negative bacteria, spore-forming bacteria, and fungi has been verified in some previous publications, indicating the potential use of these extracts as natural antimicrobial agents in various food systems [7,8,10,11]. A few years ago, Liu et al and Wang et al demonstrated that D. fruticosa leaf extracts when combined with green tea polyphenols or Ginkgo biloba extracts show synergistic, additive, and antagonistic effects on a variety of oxidation systems [12][13][14]. The reported bioactivity of these extracts is typically attributed to the high phenolic content of this plant.…”

Recent Analytical Approaches for the Study of Bioavailability and Metabolism of Bioactive Phenolic Compounds

“…In g urine samples are usually collected after establishing several time intervals for bette itoring of metabolite excretion. In the case of urine in human models, it is mostly co at the following intervals: (0-2), (2-5), (5)(6)(7)(8) and (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24) h. In animal assays, they are u Urine samples are of special interest, since the excreted metabolites may be a reflection of the metabolic transformations produced in the original compounds of the extract. Regarding this type of sample, there are studies that use only a single interval of sample collection [59,60] and studies that use multiple collection intervals [58,61].…”

“…Many of these studies have demonstrated the pleiotropic character of many bioactive compounds, which are capable of presenting beneficial effects on various therapeutic targets [7]. On the other hand, there are also in vitro studies that have attributed the bioactivity to a synergistic effect between several compounds; however, the mechanisms of action of these effects should be explored in greater depth [8,9]. Once the potential extracts are also chemically well characterized, these or the compounds that have shown beneficial effects are usually selected for further evaluation in animal models [10,11] and, finally, in clinical trials with humans [12,13].…”